Detectable warning areas (DWAs) are integral surface features built in or applied to walking surfaces or other elements to warn individuals with visual impairments of hazards on a circulation path. DWAs are often standardized and typically include raised features, such as domes. DWAs are generally found along a sidewalk, near a curb, before a road or door at an airport or train station, or along other circulation paths.
Truncated domes are a uniform standard that have been chosen by the federal government over all others as the only approved surface texture allowed under specified criteria such that “continuity” of design for the visually impaired is maintained. According to the Americans with Disabilities Act Accessibility Guidelines (ADAAG), truncated domes are to be placed around hazardous vehicular ways, access ramps, transit platform edges, and where predetermined edge protection is required.
Existing methods to form DWAs include using an epoxy-based dome material in a relatively rigid, re-usable template made of hard rubber. The dome material is applied to the template using a squeeze bottle, and then the template is removed almost immediately and the dome material is allowed to cure after the template is removed. While curing, the dome material can rise, such that it no longer takes the same shape as the template.